This invention relates to a cyanate resin composition. The cyanate resin of this invention is particularly useful as a resin for laminates in the electric and electronic fields in which low-dielectric property is required, and is also applicable to uses of sealing and molding.
Among the thermosetting resin compositions which have heretofore been used in the electric and electronic fields, the materials for printed wiring base board are mainly combinations of bisphenol type epoxy resins with dicyandiamides and adducts of bismaleimide compounds and amine compounds. Recently, accompanying the multilayering of printed wiring boards, the resins therefor have seen required to have low-dielectric property mainly for the purpose of increasing the signal transfer rate. In the conventional thermosetting resin compositions, it is wellknown to add a low-dielectric thermoplastic resin thereto for meeting such requirements. However, according to this method, such a disadvantage has been pointed out that the heat resistance of the thermosetting resin is impaired, and hence, the resulting resin composition has not sufficiently satisfied the requirement of a low-dielectric resin withstanding practical use.
Under such circumstances, a cyanate resin has been developed and is disclosed in German Patent No. 2533122, WO 88/05443 and the like. Cyanate resins which are now generally used are dicyanates of bisphenol A which have a relatively low-dielectric property. However, the enhancement of computer technique results in a requirement for much lower-dielectric property.